Ok, been wracking my head for a week now researching PSU's and I am stunned beyond recognition at the sheer level of reviews on them. Soo many that have bad remarks due to being DOA. With that many reports stating so I have to wonder, are the all these PSU's truely this bad, or am I reading the posts of sheer idiodicy and the reason these people have this much trouble is cause they have no friggin clue.

I will be utilizing about 4 of the USB slots for components and periphials

I've used several calculators to determine the rating for the PSU I will need. Each time it states 500, and have been advised to aim for 650-750 ratings. But which one will fit the bill? Especially with how difficult it is to find PSU's that fit/reach being bottom mounted. I know I will need one that is crossfire ready, but will modular truely be needed? I've researched Roswell, OCZ, Antec, Cool Master, and Corsair, but have also noticed a rediculous amount of bad reviews PSU's get (and that's ignoring the "I didn't get my rebate" whine, and similar nonsense).

nVidia video drivers FAIL, click for more infoDisclaimer: All answers and suggestions are provided by an enthusiastic amateur and are therefore without warranty either explicit or implicit. Basically you use my suggestions at your own risk.

None of those have the 4x 6pin PCI-E he'll need for 2x 6870's. Almost all have 2x 6+2 so he could just split them down to 2x 6pin each but it would be easier to get one with 4x 6pin already.Just stepping up to the 750W Corsair seems to fix the problem there.

nVidia video drivers FAIL, click for more infoDisclaimer: All answers and suggestions are provided by an enthusiastic amateur and are therefore without warranty either explicit or implicit. Basically you use my suggestions at your own risk.

There are a *lot* of crap PSUs on the market; even among some of the more respected brands, there have been problematic models. In general, you get what you pay for; if you see a 600W unit selling for $30, it's a scam.

Stick to brands that consistently get recommended on established web sites, and you'll be OK 9 times out of 10.

My own personal take -- Seasonic and PCP&C are the cream of the crop, with long track records in the business. Corsair seems to be selling some good units these days. Based on what I've seen here and elsewhere Antec seems to have gotten their act back together, though they have yet to regain my trust (I got burned by a number of dodgy Antec PSUs several years back). Ultra (TigerDirect/CompUSA's house brand) and CoolerMaster are making some affordable units that offer good value for the money if you're on a budget.

I've been meaning to try Rosewill (Newegg's house brand); I've generally been pleased with other Rosewill products I've bought, but I have yet to try their PSUs.

The only PSU brand that is solidly on my "avoid" list these days is Thermaltake (they've pissed me off multiple times a lot more recently than Antec), but there are a lot of other "off brand" PSUs that I have no experience with whatsoever, so don't take the fact that I *haven't* mentioned a brand at all as an endorsement.

The years just pass like trains. I wave, but they don't slow down.-- Steven Wilson

Thank you for all those suggestions, everyone. Budget is somewhat of a concern, but I am definitly more interested in performance that will last and not fry my system. I do have a series a questions though ...

SeaSonic M12II 650 SS-650AM 650W - I noticed this PSU is SLI ready, but not crossfire ready. Considering I plan to expand into a crossfire setup, should I not aim for PSU's that are crossfire ready?

PC Power and Cooling Silencer Mk II 750W - Crossfire ready & 7 yr warranty? This one has my attention. The reports of an average 2 yr lifespan worries me a tad though.

OCZ ZS Series 750W, OCZ ZT Series 750W, & OCZ Fatal1ty 750W - The first is crossfire ready. The following two are not, and I have heard WAY too many bad things about OCZ to seriously consider them, despite a one of the PSU's having a5 yr warranty. OCZ is creeping very close on my "do not bother with any of their products" list due to the sheer amount of bad reports I keep hearing from trusted sources.

Antec EarthWatts Series EA-750 Green 750W - crossfire ready, but only a 3 yr warranty. I have mixed feelings about this PSU.

I have Pc Power 750W power supply in my system. The power supply is about four years old, it is rock sold, quiet, and two years ago I built a new system, except the power supply. System specs Phenom II X6 1090T over clocked to 3.8 Ghz, 8 GB memory, factory over clocked Gigabyte 5850 video card, and four hard drives.

SLI and Crossfire cert. is just what it says: a formal submission process and granting of a labeling right= certification.Adds extra cost and time to the PSU, and really doesn't mean anything in particular.

Most new units are 6+2 on the eight pin PCIE = fine for your six pin card.

5 year warranty.

FYI background:This is the first superflower OEM unit made for Rosewell, the house brand of Newegg.While Rosewill is not always known for absolute best quality, in this case it is a very solid OEM.

Edit:PS the AMD 6870 is only a 140 watt card max. in Crossfire it will be well less than the 2x of that figure closer to 250 watts than 300. (unless you are folding or or distributed compute.)Consequently you will never see more than 500 watts from your described rig gaming usage.

On a slightly broader note, what is the difference between 1 12V rail and 2 12V rails?

A single 12V rail PSU has the capability of sending all 12V current down one set of plugs, whereas multiple-rail systems will have 3 or 4 separate 12V leads, but each will be limited to 20A or so.

The single-rail technically violates specifications, as the possibility exists that any 12V wire may be asked to carry far more current than is safe for the size of the wire. The multiple-rail stops this potential, but runs the potential of overdrawing the 12V on that leg depending on what you've plugged into that leg.

Never ask a woman who is eating ice cream straight from the carton how she's doing.

However, if you have a very powerful graphics card, and strict over-current protection on a rail, it has been known to cause problems.It doesn't happen very often, and was mostly due to poor design in the past.Single rail design was the pendulum swing of over-correction.

Only 16 A per rail caused a Nvidia 570 card to shut the system down under heavy load.

The OP could not be convinced that his "600 watt" (really on 504 watt available on the 12V) could not run the 240 + watt card.Had it been single rail design, he never would have run into the problem.

regarding safety,

Many wires and solder parts are going to fail before you burn down your house.Sure it is more dangerous to have all the wattage available at once, but in practice, I have never heard of an actual incident. (fire, electrocution) attributed to a single verse multi-rail PSU.

Many wires and solder parts are going to fail before you burn down your house.Sure it is more dangerous to have all the wattage available at once, but in practice, I have never heard of an actual incident. (fire, electrocution) attributed to a single verse multi-rail PSU.

Your PC has an integral containment vessel, known as "the case". Unless your case is made of cardboard, any destruction due to an overloaded single-rail PSU (other than possibly some incidental smoke) is going to be limited to the inside of your PC.

And you'd *really* have to work at it to electrocute yourself with 12V. I figure it would probably take some mad self-surgery skills, as you would likely need to insert metal electrodes attached to the 12V rail directly into your own chest cavity.

The years just pass like trains. I wave, but they don't slow down.-- Steven Wilson

My guess is that it is simple economics -- single-rail results in fewer RMAs. The insignificant number of people who manage to melt the PSU wiring because they've got a short somewhere is dwarfed by the number of people who think the PSU is defective because there isn't enough juice available on the PCIe connectors to run their bleeding edge video cards, even though they're within the overall wattage spec of the PSU.

The years just pass like trains. I wave, but they don't slow down.-- Steven Wilson

My Fortron HEXA 500W is probably busted, so I've returned it and I'm waiting for the refund. While waiting, a took a quick look around some local etailers for a replacement. So which of these would you recommend? Please note that I'm in a pretty tough financial situation this month. The refund is worth $55 and I'm willing to pay an extra $20 max. for a new PSU. The best ones I've found at the local etailers are

All of these PSU are in the $70-S75 price range, have 500W, most of them have 80% efficiency, active PFC , long sleeved cables, and 2 x PCI-E 6+2 connectors. Basically they meet my needs, but your opinions are more than welcome. So please fire away